measuring stress in a gear 2

[freddyolen]

Any one has any experience with measuring stresses in the tooth foothradius of a gear while gear is being tested on a electric pulsator-rig?

Gear is modulus 2.5!

Possible methods are strain-gauges, ESPI ...

Other methods ??

 

[plasgears]

Many years ago they spoke of photoelastic modeling for visualizing stress in parts under strain. This was one of the methods useds to develop SCF before the arrival of FEA. You may want to dust off some old references. Under strain you could see and photograph fringe lines, which represented relative strain. I can visualize a video record that can be examined frame by frame.

 

[SJLeemans]

Photoelasticity came to mind for me, as well; however, you need to have access to the right material, equipment and expertrise. There are still a few experts out there, if you can find one. Try a good engineering university. You should also be able to find a few labs that can do the work for you. That is the best place to start.

Another technique that comes to mind is Brittle Coatings. These are applied to the structure - usually sprayed. When the parts are loaded, cracks for in the coating perpendicular the the principal axes of the stress / strain field. Like, Photoelasticity, you can then determine the strains and stresses fron the crack field.

There are also thermographic techniques that might work; but I'm not well versed with those.

A good book on many experimental techniques is:
"Experimental Stress Analysis" by James W. Dally and William F. Riley.

 

[SJLeemans]

Here is a company worth looking at for a possible solution for your analysis:

http://www.stressphotonics.com

They supply and support thermoelastic and photoelastic equipment and analyses